1. Field of the Invention
The present invention relates to recording apparatus and methods having low power consumption, and more particularly to recording apparatus and method using digital memory and having low power consumption.
2. Description of Related Art
A variety of computer systems are well known, including the popular IBM-compatible type of personal computer system based on the x86 family of microprocessors available from Intel Corporation of Santa Clara, Calif. and other suppliers; the Apple Macintosh personal computer systems available from Apple Computer Inc. of Cupertino, Calif.; and the PowerPC personal computer systems available from Apple Computer Inc. of Cupertino, Calif. These computer systems support a variety of communications devices, including facsimile and telephone answering devices. These communications devices may be external or internal, and may be implemented in chip sets on the motherboard, as expansion boards (add-on cards) compliant with ISA, EISA or PCI specifications, or as add-on cards compliant with the Personal Computer Memory Card International Association specification, or "PCMCIA" specification. When a facsimile or telephone call is received, the communications device answer the line, digitizes the incoming transmission, processes the digitized transmission to obtain a bit map of a document where the incoming transmission is a facsimile, and stores the digital information on the RAM and hard disk of the host.
Mobile telephones are popular because they are immediately accessible to the user. Even so, answering a call on the mobile telephone is at times inconvenient or impossible. Answering machines have been used with mobile telephones to receive and record incoming calls when users are unable to take the calls. In one case, the answering machine is essentially a conventional unit modified to draw its power from the accessories outlet of an automobile and to plug into the peripheral interface port or accessories port of a mobile telephone. In another case, the answering machine is integrated into the mobile telephone. However, neither of these solutions is entirely satisfactory. The external essentially conventional answering machine is cumbersome and consumes a significant amount of power since it uses tape, conventional Flash memory, or a combination for storing the outgoing and incoming messages. The integrated answering machine can only be used with the mobile telephone into which it is built, and hastens depletion of the battery when in use because of its use of conventional Flash memory. Moreover, these answering machines are incapable of receiving facsimile transmissions.
Answering machines are commonly used with stationary telephones, either as separate units or integrated with the telephone, and typically are powered from the power mains. An answering machine powered off of the power mains becomes inoperative when a power failure occurs, even though the telephone to which it is connected remains operational. While an answering machine that is battery powered or has a battery backup will continue to operate in the event of a power failure, this is not a reliable solution since the answering machine will not function if the battery is allowed to discharge through neglect or frequent use.
Devices for recording voice and facsimile are available for use in personal and business computer systems. These devices typically store information on the hard disk of the host computer system. This approach avoids the need for expensive memory dedicated to the recording device, and makes available to the recording device an enormous amount of memory. However, a disadvantage, particularly to consumers and businesses concerned about energy conservation, is that such computer systems must be continuously and reliably powered up, even while not being used for normal office and personal tasks.
Accordingly, a need exists for a recording apparatus and method that provides reliable recording of voice and facsimile and is not reliant on the power mains for its power.